Humans contract West Nile when they are bitten by mosquitoes infected with the virus. When people are infected with West Nile, the virus will affect them one of three ways. West Nile neuroinvasive disease is the most serious type, infecting the brain and spinal cord. Neuroinvasive disease can lead to death, paralysis and brain damage. The milder viral infection is West Nile fever, in which people experience flu-like symptoms. The majority of people who contract West Nile will be asymptomatic, which means they show no symptoms. These cases are typically detected through blood donations or in the course of other routine medical tests.

About 90 percent of all cases are asymptomatic, while about 10 percent will develop West Nile fever. Only a very small number of infected individuals will show the serious symptoms associated with the neuroinvasive disease. Residents who are 65 years old and older are at higher risk for complications, but everyone is at risk for infection.

Safety Tips

Protecting Yourself

If you will be outside, you should wear a mosquito repellent containing DEET. The American Academy of Pediatrics (AAP) recommends that repellents should contain no more than 30 percent DEET when used on children. Insect repellents also are not recommended for children younger than 2 months of age. CDC recommends that you always follow the recommendations appearing on the product label when using repellent.

Apply repellent on exposed skin and clothing. Do not apply under your clothes or on broken skin.

To apply repellent to your face, spray on your hands and then rub on your face, avoiding your eyes.

Adults should always apply repellent to children.

Wear long-sleeved shirts and pants when outdoors for long periods of time.

Avoid perfumes and colognes when outdoors for extended periods of time.

Make sure that your house has tight-fitting windows and doors, and that all screens are free of holes.

Protecting Your Home

Reduce the mosquito population by eliminating standing water around your home, which is where mosquitoes breed.

Dispose of tin cans, ceramic pots and other unnecessary containers that have accumulated on your property. Turn over wheelbarrows, plastic wading pools, buckets, trash cans, children's toys or anything that could collect water.

Drill holes in the bottom of outdoor recycling containers. Drainage holes that are located on the container sides collect enough water for mosquitoes to breed.

Check and clean roof gutters routinely. They are often overlooked, but can produce millions of mosquitoes each season.

Aerate ornamental pools or stock them with fish. Water gardens can become major mosquito producers if they are allowed to stagnate.

Clean and chlorinate swimming pools that are not being used. A swimming pool that is left untended by a family for a month can produce enough mosquitoes to result in neighborhood-wide complaints. Be aware that mosquitoes may even breed in the water that collects on swimming pool covers.